LAST EDIT Apr 26 2021

Stream Chat has built-in support for user Reactions. Common examples are likes, comments, loves, etc. Reactions can be customized so that you are able to use any type of reaction your application requires.

Similar to other objects in Stream Chat, reactions allow you to add custom data to the reaction of your choice. This is helpful if you want to customize the reaction logic.

message_idstringID of the message to react to
reactionobjectReaction object
reaction.typestringType of the reaction. User could have only 1 reaction of each type per message
reaction.scoreintegerScore of the reaction for cumulative reactions (see example below)1
user_idstringUser ID for server side calls
enforce_uniquebooleanIf set to true, new reaction will replace all reactions the user has (if any) on this messagefalse
Custom data for reactions is limited to 1KB.

Removing a Reaction


Paginating Reactions


Messages returned by the APIs automatically include the 10 most recent reactions. You can also retrieve more reactions and paginate using the following logic:

Cumulative (Clap) Reactions


You can use the Reactions API to build something similar to Medium's clap reactions. If you are not familiar with this, Medium allows you to clap articles more than once and shows the sum of all claps from all users.

To do this, you only need to include a score for the reaction (ie. user X clapped 25 times) and the API will return the sum of all reaction scores as well as each user individual scores (ie. clapped 475 times, user Y clapped 14 times).